Walgreen, others sue Pfizer over depression drug

(Reuters) - Pfizer Inc and Teva Pharmceutical Industries Ltd were sued by Walgreen Co and four other large retailers, accused of violating U.S. antitrust law by conspiring to keep generic versions of a popular antidepressant off the shelves.

In a complaint made public on Thursday by the U.S. District Court in Trenton, New Jersey, the retailers said Wyeth kept generic equivalents off the market for at least two years after its marketing exclusivity for the original Effexor compound patent lapsed in June 2008.

They said Wyeth did this by obtaining fraudulent patents, engaging in sham litigation, and entering a price-fixing agreement with Teva to delay cheaper generic equivalents from reaching the market.

"As a result of defendants' exclusionary conduct, generic versions of Effexor XR were illegally blocked from the marketplace from June 2008 through at least June 2010," when U.S. sales of the drug topped $2.5 billion, the 78-page complaint said. Pfizer bought Wyeth in 2009.

Some of the retailers' claims had been assigned to them by three large drug wholesalers: AmerisourceBergen Corp, Cardinal Health Inc and McKesson Corp. A sixth plaintiff is American Sales Co, another wholesaler.

Effexor XR is used to treat depression and three anxiety disorders. Its chemical name is venlafaxine hydrochloride.

"Pfizer categorically denies the claims asserted in the plaintiffs' complaints," spokesman Christopher Loder said in an emailed statement. "Wyeth obtained its patents protecting Effexor XR lawfully, and the company intends to defend itself vigorously against these claims."

Teva spokeswoman Denise Bradley said that company believes the lawsuit has no merit.

Pfizer's global sales of Effexor XR totaled $537 million from January to September, down 64 percent from a year earlier, reflecting increased generic competition.

Pfizer is based in New York, while Wyeth has operations in Madison, New Jersey. Walgreen is based in Deerfield, Illinois; Kroger in Cincinnati; Safeway in Pleasanton, California; Supervalu in Eden Prairie, Minnesota; independently-owned HEB in San Antonio; and American Sales in Lancaster, New York.

The case is Walgreen Co et al v. Wyeth Inc et al, U.S. District Court, District of New Jersey, No. 11-06958.